Package com.github.mhewedy.expressions

Class Expression

java.lang.Object

com.github.mhewedy.expressions.Expression

public abstract class Expression
extends Object

Expression class considered the base for all other expressions as well as contains factory method to build the expressions object.

So it represents the java api for the expressions

Example: We can build complex expressions and pass it to the spring data jpa ExpressionsRepository.findAll(Expressions) using the factory methods in this class as following:

 var expressions = Expression.of("lastName", Operator.$eq, "ibrahim")
         .and(Expression.or(
                 Expression.of("age", Operator.$in, 10, 20),
                 Expression.of("birthDate", Operator.$lt, LocalDate.of(1980, 1, 1)))
         ).build();
 

Then the output could be represented as:

 where lastName = "ibrahim" and (age in (10 , 20) or birth_date < "1980-01-01")
 

The Expression API also service as an intermediate representations that resides between the Expressions and the spring data JPA specifications implementation ExpressionsPredicateBuilder.

Constructor Summary

Constructors

Constructor	Description
Expression()

Method Summary

Modifier and Type	Method	Description
Expression	and(Expression expression)	apply "and" on current expression with the parameter expression.
static Expression	and(Expression... expressions)	factory method used to create new expression that "and" all input expressions.
Expressions	build()	Convert current object to Expressions to be used by the ExpressionsRepository.
static Expression	of(String field, Operator operator, Number value)
static Expression	of(String field, Operator operator, Number... values)	Used with operators require list of elements, such as Operator.$in and Operator.$nin
static Expression	of(String field, Operator operator, String value)
static Expression	of(String field, Operator operator, String... values)	Used with operators require list of elements, such as Operator.$in and Operator.$nin
static Expression	of(String field, Operator operator, java.time.temporal.Temporal value)
static Expression	of(String field, Operator operator, java.time.temporal.Temporal... values)	Used with operators require list of elements, such as Operator.$in and Operator.$nin
Expression	or(Expression expression)	apply "or" on current expression with the parameter expression.
static Expression	or(Expression... expressions)	factory method used to create new expression that "or" all input expressions.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Expression

public Expression()

Method Detail

of

public static Expression of(String field,
                            Operator operator,
                            String value)

of

public static Expression of(String field,
                            Operator operator,
                            Number value)

of

public static Expression of(String field,
                            Operator operator,
                            java.time.temporal.Temporal value)

of

public static Expression of(String field,
                            Operator operator,
                            String... values)

Used with operators require list of elements, such as Operator.$in and Operator.$nin

of

public static Expression of(String field,
                            Operator operator,
                            Number... values)

Used with operators require list of elements, such as Operator.$in and Operator.$nin

of

public static Expression of(String field,
                            Operator operator,
                            java.time.temporal.Temporal... values)

Used with operators require list of elements, such as Operator.$in and Operator.$nin

and

public static Expression and(Expression... expressions)

factory method used to create new expression that "and" all input expressions.

or

public static Expression or(Expression... expressions)

factory method used to create new expression that "or" all input expressions.

and

public Expression and(Expression expression)

apply "and" on current expression with the parameter expression.

or

public Expression or(Expression expression)

apply "or" on current expression with the parameter expression.

build

public Expressions build()

Convert current object to Expressions to be used by the ExpressionsRepository.